The purpose of this project is to use fluorescence and/or phosphorescence methods to investigate problems of interest in biomedical areas. Recent work has included: 1. Study of cationic fluorescent dyes such as Auramine O, as fluorescent probes of proteins. Serum albumin and alcohol dehydrogenases were studied. 2. Study of DPH, diphenylhexatriene, a fluorescent probe which has an affinity for lipids and hydrophobic areas of proteins. 3. The study of red cell membrane fluidity, and the effect of lipid feeding on this parameter in dogs undergoing experimental atherosclerosis. BIBLIOGRAPHIC REFERENCE: Chen, R.F.: Fluorescence of Free and Protein Bound Auramine O. Arch. Biochem. Biophys. 179: 672-681, 1977.